(1) The flowers grow in a raceme , an unbranched stalk that blooms from the bottom up.

(2) All three species have similar flower phenology: in general, the terminal raceme matures acropetally and the flowers are first staminate, then pistillate, and the sexual stages do not overlap within the flower.

(3) Flowers emerge on terminal racemes and are subtended by small bracts.

(4) In both experiments, flowers on racemes from main stem nodes in the middle of the canopy were tagged before anthesis and their development and growth were monitored.

(5) In summer, the tall flower stems bear racemes of up to 20 huge, strongly perfumed, white, trumpet-shaped flowers with glossy green leaves.